The present invention relates to the field of packaging of measured quantities of similar articles, especially small articles such as push-pins, nails, etc. In particular, the invention provides an apparatus for automatic discharge of such articles into containers.
Small articles such as push-pins, and the like, are packaged and sold in measured quantities. It is known to use an electronic counting device which counts the articles as they are fed from a hopper. The counter opens a gate to allow a batch of articles to fall into a container. Examples of such counters are given in U.S. Pat. Nos. 3,618,819, 4,180,153, 3,730,386, and 3,823,844, and in U.S. patent application Ser. No. 07/322,715, filed Mar. 13, 1989 U.S. Pat. No. 4,982,412, entitled. "Apparatus and Method for Counting a Plurality of Similar Articles". The above-cited items are incorporated by reference herein.
It is often necessary to package measured amounts of different articles in the same container. For example, one might need to provide a filled with 100 nails and 100 tacks. In this case, two count-container ers are used, one for the nails and one for the tacks. Each counter must be programmed to dump its articles, and the dumping of both counters should be coordinated so that each package has the required number of nails and tacks.
It has been known to increase the rate at which articles are processed by providing a plurality of counters, and distributing the articles to be discharged among the several counters. However, for each counter, the time to dump a batch of articles is fixed, and reducing the number of articles processed by each counter effectively increases the fraction of time spent by each counter in dumping the articles. Thus, it turns out that the effective feed rate obtained with n counters is less than n times the rate that would be obtained with a single counter.
A preferred means of using multiple counters is to arrange for each counter to count a full complement of articles, and to program the counters to discharge the articles in an alternating manner. With this method, each counter spends the same percentage of its time dumping articles as would be spent by a single-counter system, and the single-system feed rate can be multiplied by the number of counters to obtain the new feed rate. The result is that the system counts and discharges the same number of parts in much less time.
Programming the counters to alternate in discharging articles is not as simple as it would seem. Even a set of identical counters will not take the same time to count the same number of articles, and each counter will not, in general, require the same counting time from one batch of articles to the next. An efficient system must take these variations into account. The counting and dumping devices of the prior art have not solved the problem of coordinating the operations of a series of counters, to function in the manner described above.
The present invention solves the above-described problems. The invention includes an automated system for discharge of articles, the system allowing the efficient use of a plurality of counters. The system allows all the counters to operate in an alternating manner, or simultaneously, or using a combination of alternating and simultaneous actions. The system uses a data transmission method which is simple and rapid. The system can be used to discharge many different types of articles, and can be used with a wide variety of electronic counters.